Elevating truck



April 22 1924. 1,491,384

F. EIDMANN ELEVAT I NG TRUCK Filed Nov. 26 1920 v a U INVENTOR M1 Maw W0 rw ATTORNEYS.

Patented Apr. 22, 1924.

UNITED STATES PATENT FF'IQE. V

FRANK I4. EIDMANN, OF EOLYOKE, MASSACHUSETTS, ASSIGNO'R T EDWARD N.WRITE, J. LEWIS WYGKOFF, AND JAMES M. EATON, ALL OF HOLYQKE, MASSACHU-SETTS, TRUSTEES, DOING BUSINESS AS COWAN TRUCK COMPANY.

ELEVATING TRUCK.

application filed November 26, 1920.- Serial No. 426,583.

ably arranged gripping and elevating arms are employed to raise or lowerarticles of considerable weight.

One object of the invention is to provide improved controlling mechanismto limit the movement of the-elevating a-rms away from each other andthus insure proper operation of the mechanism and prevent injury to thesame.

Another object of the invention is to provide suitablepositively-actuated mechanism for controllin" the operation ofthe motorfrom one of t e moving parts of the mechan m, while at the same timepermitting Sue manual control of the motor as may be desirable for thefurther operation of the mechanism.

Another object of the invention is to provide suitableautomatically-controlled brakeoperating mechanism and adapt the same tobe applied to the motor-shaft coincident with the cutting off of thecurrent through the windings of the motor.

Further objects of the invention relate to certain improved details ofconstruction and improved methods of operation as will be more fully setforth in the detailed description to follow.

Referring to the drawings:

Fig. 1 is a side elevational vlew of the truck, showing the elevatingarms in raised and lowered position, certain of the parts being brokenaway to better illustrate certaincontrol mechanism'for controlling themovement of the arm; and

Fig. 2 is a top plan view of the structure.

In the operation of the devices of this character whereswingingly-mounted elevating arms movable .towards and from each otherare employed in lifting and transporting articles of-considerableweight, it is de-' sirable to provide proper control mechanism forpreventing excessive movement of the arms outwardly from each otherwhich being ofmassive construction to counterbalance such heavy articlesas may might otherwise cause injury to the mechanism. In providingsuchvcontrol mechanism it has also been found desirable to provide meansfor preventing accidental operation of the mechanism by the operator tocause excessive outward movement of the arms, and also to suitablycoordinate the control mechanism with means for positively preventingfurther rotation of the motor-shaft when the arms have reached the limitof their outward movement.

In the embodiment of the invention illustrated herewith, the truck isshown as comprising any suitable form t of supporting frame 1, mounted,to travel upon properly arranged front wheels 2 and rear wheels 3,

certain of which wheels may be steered by 4 any suitable arrangement ofsteering mechanism, and certain of said wheels being preferably adaptedto be driven for the purpose of moving the truck-from place to place andtransport the articles, as maybe found desirable. upon the forward endof the frame 1 and is adapted to enclose the usual steering, driving andcontrol mechanism for moving the truck from place to place. An operators platform 5 projects forwardly of the truck and is so located thatthe operator may have ready access to the steering handle and the othercontrol mechanism for operating the elevating arms. Trucks of this typeare designed for moving .articles of considerable weight and areconsequently so constructed as to withstand considerable strain, besidessuccessfully be raised and lowered by the truck.

Supported upon opposite sides of the rear end portion of the frame 1 isa pair of similar castings 6 and 7 adapted to support certain of theoperating mechanism for actu- A. horizontal ating the elevating arms.shaft 8 extends transversely of the frame 1 and is rotatably supportedby suitable bearings 9 and 10 formed in the castings 6 and 7,respectively. A large worm-gear 11 is se-' cured to or formed integralwith the shaft 8, being located substantially centrally thereof andarranged'to mesh with and be driven by a worm 12 carried by acounter-shaft 13 suitably supported in bearings 14 and 15 from theframe. A worm-gear 16 is keyed or otherwise suitably secured to theshaft 'A casing 4 is positioned in meshing-en agement with a worm 17carried by the'sha t 18 of the motor 19. The

motor 19 and the motor-shaft 18 are suitmoving the elevating armstogether with the articles which they are adapted to handle.

The shaft 8 has an enlarged portion 20 formed upon one side of thecentral gear 11 and provided upon its exterior surface with a right-handthread, while a similar enlarged portion 21, located upon theoppositeside of the gear 11 is provided with a left-hand thread upon itsexterior surface. A pair I of swingingly-mounted elevating arms 22 and23, of symmetrical construction, are each provided with an internally--threaded opening adjacent one end thereof, whereby theinternally-threaded end portions ofthe arms may be threaded upon theportions 20 and 21, respectively, of the shaft 8. Thevertically-swinging arms 22 and-23 are each provided with a gripping jaw25 and 26 respectively for gripping the articles to be raised orlowered, said jawsbeing rotatably supported by trunnions, 27 and 28respectively, mounted in the rearwardly-pro jecting ends of theswingingly-mounted arms. The jaws 25 and 26 are of symmetrical form andare each pivotally supported fromthe corresponding swinging arm at apoint somewhat off center so that the weight of the jaws. normallycauses them to assume the position as shown in Fig. 1 of the drawings.In the present embodiment of the invention, the interior surfaces of thegripping jaws are somewhat concave, for the purpose of enabling themetomore readily engage a cylindrical object A, such as a roll of paper, forraising or lowering the same or conveying 'it from place to place. Thegripping jaws are, as above stated. pivotallyemounted upon therearwardly extending end portions of the elevating arms and suitablemeans may be provided for locking the gripping jaws to the correspondingelevating arms in 7 any one of a variety of angular positions,

such for example, as that shown and described in my copendingapplication Serial No. 426,582 filed Nov. 26, 1920.

The motor 19 is adapted to operate with equal readiness in either aforward or reverse direction, whereby the gear 11 and the shaft 8 bywhich the'same is carried may be rotated either in a clockwise orcounterclockwisedirection as seen in Fig. 1 of the drawings. \Vhen thedevice is to be used for the purpose of raising an object such as thatdesignated by the reference character A in the embodimentillustrated'herewith, the truck is placed in position and the elevatingarms, which normally occupy the lowered position as shown in full linesinv Fig.1 of the drawings--in'which position they are supported by meansof a transverse bar 50 extending across the rear portion of the grippingjaws 25 and 26 are tightly clampedagainst opposite sides of the article,whereupon the internally-threaded portions of'the elevating arms, beingincapable of further travel towards each other, become locked upon theexternally-threaded portions 20 and 21 of the shaft 8 and move with theshaft upon continued rotation of the same, to assume the positionindicated in dotted lines upon Fig. 1 of the drawings wherein thearticle iselevated, and the truck may then be moved to any desiredlocation and the article deposited upon a platform, wagon, or otherraised surface, as may be desired. Immediately upon the depositing ofthe article in the desired position, the motor 19 is caused to rotate ina reverse direction, thus rotating the shaft 8 in a counterclockwisedire:;tion as viewed in Fig. 1. whereupon the arms 22 and 23 are causedto move awa from each other until such time as he gripping jaws arereleased from the article which has been trans ported. When the grippingjaws have been released from the article, the truck may be movedforwardly out of en gagement therewith, mechanism which will behereinafter described being provided for preventing sudden fall of theelevating arms into the lowered position which they normallyoccupy'after the are moved out of engagement with the p atform, wagon,or other surface upon which the article has been deposited. v y i Theelevating arms 22 and 23 are provided with correspondingly-locatedupwardly-extending bosses 43 and 44, respectively, in which is mounted atransverse bar 45, the bar being secured against. sliding movementrelative to the boss 43 by means of a suita ble pin 46, but beingmounted to permit the bar to slide relative to the boss 44,. It will beseen upon reference to Fig. 1, that when the elevating arms are moved totheir raised position, as indicated in dotted lines in that l figure,the bar 45 will move rearwardly aboutythe shaft 8 as an axis and may beengaged by aholding member 47 pivotally supported-by the frame, asindicated at 48, to prevent sudden downward movement of the elevatingarms after they have been released from engagement with the articleraised. The holding member 47 is provided with a plurality of lugs 49 sopositioned as to be adapted to engage the bar 45 in any one of a nearestplurality of angular positions, whereby the elevating arms may beheld indifferent raised positions, depending upon the different heights towhich it may be found desirable to elevate the articles. An operatinglever .51, is mounted upon a pivot 52 carried by a. bracket 53, whichis, in turn,

supported upon the housing 4, and a link 54 pivotally connects the lever51 with the holding member 47, whereby the holding member may be heldout of engagement with the rod 45 during the elevating movement of theswinging arms and be moved into engaging position with the rod 45'whenthe swinging arms have reached the upper 'limit of their movement. A lug55 is carried by the bra-cket 53 and is suitably located to normallyhold the lever 51 in such position as to keep the member 4-7 out ofengagement with the bar- 45, while at the same time the operator by"sliding the lever 51 laterally upon the pivot 52 may lower the holdingmember 47 mto en agement with the rod 45.

Vhen. the elevating arms have reached the f upper limit of theirmovement, the operator may manipulate the lever 51 to cause the holdingmember to be lowered into such position that one of the lugs 49 engagesthe bar 45, whereby the elevating arms are held in raised position andprevented from being suddenly dropped into their normal lowered positionas the truck is moved away from the platform upon which the article hasbeen deposited. When the truck has been moved away from the platform,the motor 19 may be operated to rotate the shaft 8 in a clckwisedirection as seen in Fig. 1, thus causing the arms '22and 23. to travelinwardly towards each other-until the inner portions thereof engageopposite side faces of the worm-gear 11, when the arms will be heldagainst downward movement independently of the shaft 8, and thereuponthe motor 19 may be reversed to slowly lower the arms into their normallowered position in such a manner as to prevent breakage or injury ofthe arins as they are being lowered. I

As will be understood from the preceding description, the elevatingarms, when their movement is unobstructed, may move inwardly uponclockwise rotation of the shaft 8 until the inner surfaces of theforward end portions engage opposite sides of the gear 11, whereuponthey will be locked against further inward movement towards each otherand will then be rotated with the shaft 8 as the shaft is moved in aclockwise direction as seen in Fig. 1. In a similar manner, theoperation of the motor to rotate the shaft Bin a counterclockwisedirection, as seen in Fig. 1, will cause the elevating arms, if inlowered position, to move outwardly away from each other until theyreachthe limit of their outward movement,

and if the motor continues tooperate after the arms have reached thelimit of their .outward movement further outward movement of the armsmight cause injury to the frame or arms by further forcing themoutwardly. In order to automatically prevent excessive outward movementof the arms as thus de scribed and provide means for stoppingcounterclockwise rotation of the shaft 8 without necessitating anyaction on .the part of the operator, suitable control mechanism isprovided together with means for actuating the; same from the shaft 8.

A lug 60, suitably positioned upon the shaft 8, is adapted to strike theend. of a slidably-supported bar 61 when the shaft 8 is rotated asufiicient extent in a counterclockwisedirection to bring the arms tothe limit of their outward movement, whereby the bar 61 is movedforwardly of the truck to operate the controller for stopping theoperation of the motor. The forward end of the bar 61 is ivotallyconnected to one arm of an elbow ever 62 which is pivotally supported,as at 63, upon the housing, the other arm of said elbow-lever beingpivotally connected to the'controller 64 by means of a link 65. Thecontroller 64 is mounted to rotate a controller-shaft 66 to forward,reverse, or neutral positions, the controller being shown in Fig. 1 asin neutral position, the forward and reverse positions of the same beingindicated in dotted lines. When the operator draws theforwardly-projecting portion of the controller upwardly, current is sentthrough the motor windings to cause the motor to actuate the shaft 8 torotate the same in a counterclockwise direction, and when the lug 60strikes the end of the bar 61 the bar is forced forwardly to bring thecontroller into neutral position, as shown in full lines upon Fig. 1 ofthe drawings.

1 The motor-shaft 18 is provided with a drum 67 secured thereto, and apair of brakebands 68 are pivotally supported by a bracket 69 andpositioned to engage opposite sides ofthe drum for stopping rotation ofthe motor-shaft when current is cut off from the windings of the motor.The bands 68 are each provided withan upwardly-extending ear'70, theears being arranged substantially parallel with each other, and a bolt71 passes through the ears and has a coiled spring 72 positionedtherearound for nor mally forcingthe brake-bands together. A cam 74 ispivotally supported in any suitable manner and projectsbetween the earsfor separating the ears against the tension of the spring 72, and a link75 connects the cam 74 with the bar 61 for controlling the operation ofthe cam from the bar 61 to move the bands away from opposite sides ofthe drum when the-controller is in either forward or reverse osition'and permits the bands to be clamped against the sides of the stoppingexcessive rotation of the shaft 8 in a counterclockwise directionas'seen in F 1g. 1, which is effective to not only move the controllerfrom reverse to neutral position,

but at the same time renders effective a brake-mechanism to stoprotation of the motor-shaft. The control mechanism is at such time inposition to permit manual operation of the controller to operate themotor in a forward direction by further depressing theforwardly-extending portion of the controller 64 and thus at the sametime moving the bar 61 further forwardly to release the brakefrom themotor-shaft when the forward operation of the motor is.commenced. Whenthe controller is moved to neutral position from either forward orreverse position, the cam 7 4 is rotated to allow the brake bands 68 tobe forced against opposite sides of the drum 67 by the spring 72 forimmediately stopping rotation of the motorshaft after each operation ofthe motor.

lVhile the invention illustrated herewith has been described withconsiderable particularity in order to make clear to those skilled inthe art the various structural details which may be employed in apractical utilization of the same, it is to be understood that theinvention is not limited to the precise details of constructionillustrated and described except as they are included in the followingclaims.

What I claim is 1. In an elevatin truck, grip ing and elevating armsmounted for swinging move, ment about a common shaft, means for rotatingsaid shaft to actuate the arms, a sto carried by said shaft, and meansactuate by said stop for rendering said first-named means inoperativeupon rotation of the shaft to a predetermined extent in one direction.

2. In an elevating truck, gripping and elevating arms mounted forswinging movement about a common shaft and movable towards and from eachother, and stop mechanism operative to limit the movement of the armsaway from each other.

3. In an elevating truck, gripping and elevating arms mounted forswinging movement about a common axis and movable towards and away fromeach other, a rotatable shaft actuatable to move said arms towards and.away from each other and to swing the same, and means for limiting theextent of rotation of the shaft in one direction.

enace 4. In an elevating truck, gripping and elevating arms mounted forswinglng movement about a common axis and movable towards and away fromeach other, a rotat-. able shaft actuatable to move the arms towards andfrom each other, and stop iechanism operative to limit themovementoperating shaft adapted to be actuated by the motor, a stopcarried by said shaft, a controller for the motor, a brake for themotor-shaft, and means operable at a predetermined point in the rotationof the shaft by said stop to move the controller to neutral position andapply the brake to the motor-shaft.

7. In an elevating truck, a motor, an operating shaft adapted to bedriven from the motor, a controller for the motor movable to forward,reverse and neutral positions, and means operable at a point in therotation of the shaft to move the controller from reverse to neutralposition and hold it against being moved to reverse position whilepermitting it to be moved to forward position.

8. In an elevating truck, gripping and elevating arms mounted forswinging movement and movable towards and from each other, a rotatableshaft for moving the arms, a motor for operating said shaft,-acontroller, and means actuatable by said shaft at a predetermined pointin its rotation to move the controller to neutral position.

9. In a truck, an elevating mechanism, means for actuating the elevatingmechanism comprising a motor, an operating shaft and a stop carried bysaid shaft, a controller for the motor, and means operated by the stopfor moving the controller to neutral position.

10. In a truck, an elevating mechanism, means for actuating theelevating mechanism comprising a motor and motor-shaft, an operatingshaft and a stop carried by said shaft, a oontrolier for the motor, andmeans operated by the stop for movin the controller to neutral positionand app ying a brake to the motor-shaft.

11. In a truck, an elevating mechanism comprising gripping and elevatingarms mounted to swing in a vertical plane and movable horizontallytowards and from each other, motor-operated means for swinging the armsand moving the same towards and from each other, a controllerfor themotor, and means actuated by the motor-operated means at a predeterminedpoint in its movement for moving the controller to neutral position.

12. In a truck, an elevating mechanism comprising gripping and elevatingarms mounted to swing in a vertical plane and movable horizontallytowards and from each other, motor-operated means for swinging the armsand moving the same towards and from each other, a controller for themotor having forward, reverse, and neutral positions of movement, andmeans actuated by the motor-operated means at a predetermined point inits movement to move the controller from reverse to neutral positionwhile permitting movement of the controller to its forward position.

13. In an elevating truck, a shaft'provided with oppositely threadedportions, gripping and elevating arms mounted upon the oppositelythreaded portions of said shaft and adapted for movement towards andfrom each other longitudinally of said shaft and movable with said shaftwhen restrained from travel longitudinally thereof, and means forlimiting the rotation of said shaft in one direction.

14. In an elevating truck, a motor, an operating shaft adapted to beactuated by the motor and provided with oppositely threaded portions,gripping and elevatin arms mounted upon the opositely threade portionsof said shaft and movable towards and from each other and movable withsaid shaft when restrained from travel longitudinally thereof, acontroller for the motor, and means operable at a point in rotation ofthe shaft to move the controller to neutral position.

15. In an'elevating truck, a motor, an operating shaft adapted tobeactuated by the motor and provided with rightand lefthanded threadedportions, gripping and elevating arms'mounted upon the rightandleft-handed threaded portions of said shaft and adapted for movementtowards and from each other, a controller for the motor movable toforward, reverse and neutral positions, and means operable at a point inthe rotation of the shaft to move the controller from reverse to neutralposition and hold it against being moved to reverse position whilepermitting it to be moved to forward position.

16. In an elevating truck, a motor, an operating shaft adapted to beactuated by the motor and provided with rightand lefthanded threadedportions, gripping and elevating arms mounted upon the rightandleft-handed threaded portions of said shaft 'and adapted for movementtowards and from each other, a controller for the motor, and meansoperable at a point in the rotation of said shaft to move the controllert neutral position. 17. In a truck, a shaft provided with oppositelythreaded portions, an elevating mechanism comprising gripping andelevating arms mounted upon the oppositely threaded portions of saidshaft to swing in a vertical plane and movable horizontally towards andfrom each other, motor operated means for swinging-theanns and movingthe same towards and from each other, a controller for the motor, andmeans actuated by said shaft at a predetermined point in its movementfor moving the controller to neutral position. 1

In testimony whereof I have aflixed my signature.

- FRANK L. EIDMANN.

